Method for processing substrates using gaseous silicon scavenger

• US 6,444,137 B1
• Filed: 07/01/1996
• Issued: 09/03/2002
• Est. Priority Date: 07/31/1990
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Collins, Kenneth S., Yang, Chan-Lon, Marks, Jeffrey, Groechel, David W., Wong, Jerry Yuen-Kui, Keswick, Peter R.
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US08/673,972
• Time in Patent Office: 2,255 Days
• Field of Search: 204/298.16, 204/298.37, 204/298.34, 204/298.38, 204/298.08, 204/298.11, 156/345, 315/111.21, 315/111.41, 315/111.51, 118/723.R, 118/621, 216/67, 216/68, 216/79
• US Class Current: 216/79
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: C23C 16/517 using a combination of discharges covered by two or more of groups C23C16/503 - C23C16/515
• CPC Class Codes: H01F 2029/143 with control winding for generating magnetic bias
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3211 Antennas, e.g. particular shapes of coils
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32165 Plural frequencies
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/3222 Antennas
• CPC Class Codes: H01J 37/32293 using particular waveforms, e.g. polarised waves
• CPC Class Codes: H01J 37/32458 Vessel
• CPC Class Codes: H01J 37/32522 Temperature
• CPC Class Codes: H01J 37/3266 Magnetic control means
• CPC Class Codes: H01J 37/32688 Multi-cusp fields
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01J 37/32871 Means for trapping or directing unwanted particles
• CPC Class Codes: H01L 21/31116 : by dry-etching
• CPC Class Codes: H01L 21/6831 : using electrostatic chucks

Abstract

A plasma reactor chamber uses an antenna driven by RF energy (LF, MF, or VHF) which is inductively coupled inside the reactor dome. The antenna generates a high density, low energy plasma inside the chamber for etching oxygen-containing layers overlying non-oxygen-containing layers with high selectivity. Auxiliary RF bias energy applied to the wafer support cathode controls the cathode sheath voltage and controls the ion energy independent of density. Various magnetic and voltage processing enhancement techniques are disclosed, along with other etch processes, deposition processes and combined etch/deposition processes. The disclosed invention provides processing of sensitive devices without damage and without microloading, thus providing increased yields. Etching of an oxygen-containing layer overlying a non-oxygen-containing layer can be achieved with high selectivity.

Claims

1. A plasma etch process comprising:

a) providing a vacuum chamber for forming and maintaining a plasma therein;

b) providing an article to be processed by said plasma on a support in the chamber;

c) supplying a fluorine-containing etch gas to the chamber;

d) coupling RF energy into the chamber for forming and maintaining a plasma of said etch gas in the chamber; and

e) supplying to the chamber a gaseous source of silicon or carbon in addition to said etch gas so as to form a passivating polymer on said article.

2. An etch process according to claim 1 wherein the etch gas is a fluorocarbon.

3. An etch process according to claim 2 wherein the etch gas contains only fluorine, carbon and hydrogen.

4. An etch process according to claim 2 wherein the etch gas contains only fluorine and carbon.

5. An etch process according to claim 1 wherein said gaseous source of silicon is selected from at least one member of the group consisting of silane, tetraethoxysilane, diethylsilane and silicon tetrafluoride.

6. An etch process according to claim 1 wherein said gaseous source of silicon is selected from at least two members of the group consisting of silane, tetraethoxysilane, diethylsilane and silicon tetrafluoride.

7. An etch process according to claim 1 wherein a solid source of silicon or carbon is present in the plasma region of the chamber and is independently treated to maintain a surface thereof to be reactive.

8. An etch process according to claim 1 wherein said passivating polymer is a carbon-rich polymer.

9. An etch process according to claim 8 wherein said passivating polymer contains more than 50% by weight of carbon and 40% by weight or less of fluorine.

10. A plasma etch process comprising;

a) providing a vacuum chamber for generating a plasma;

b) supporting an article to be processed on a support in the chamber;

c) supplying a fluorine-containing gas to the chamber;

d) supplying a silicon-containing gas to the chamber so as to form a passivating polymer on the surface of said article; and

e) coupling RF energy into the chamber for maintaining a plasma in said chamber for processing said article.

11. An etch process according to claim 10 wherein said RF energy is coupled into said chamber via said support.

12. An etch process according to claim 10 wherein said coupling step inductively couples said RF energy from a coil antenna into the chamber.

13. An etch process according to claim 10 wherein RF energy is electromagnetically coupled from an RF power supply into the chamber.

14. An etch process according to claim 10 wherein said silicon-containing gas is selected from one or more members of the group consisting of silane, tetraethoxysilane, diethylsilane and silicon tetrafluoride.

15. An etch process according to claim 10 wherein said passivating polymer is a carbon-rich polymer.

16. An etch process according to claim 15 wherein said passivating polymer contains more than 50% by weight of carbon and 40% by weight or less of fluorine.

17. A plasma etch process comprising:

a) providing a vacuum chamber for forming and maintaining a plasma therein;

b) providing an article having an oxygen-containing layer over a non-oxygen-containing layer thereon to be processed by said plasma on a support in said chamber;

c) supplying a fluorine-containing etch gas to the chamber;

d) coupling RF energy into the chamber for forming and maintaining a plasma of said etch gas in the chamber; and

e) supplying to the chamber a fluorine-consuming silicon or carbon-containing gas in addition to said etch gas so as to form a selectivity-enhancing polymer on said article to selectively etch the oxygen-containing layer.

18. An etch process according to claim 17 wherein said oxygen-containing layer is silicon oxide.

19. An etch process according to claim 18 wherein said non-oxygen-containing layer contains silicon.